Here's why:

* Dome Shape: Mount St. Helens is known for its distinctive dome-shaped summit, which is formed by the slow extrusion of viscous lava.

* Explosive Eruptions: While dome volcanoes are often associated with slower, effusive eruptions, Mount St. Helens is also known for its explosive eruptions, which can be incredibly powerful and destructive.

* History of Eruptions: Mount St. Helens has had a long history of eruptions, with the most famous being the devastating 1980 eruption that caused significant damage and loss of life.

Other examples of dome volcanoes include:

* Mount Lassen Peak, California, USA

* Soufrière Hills Volcano, Montserrat

* Unzen, Japan

* Mount Pelée, Martinique

These volcanoes all share the characteristic dome shape and can exhibit varying levels of explosive activity.